Bulletin of Insectology 61 (2): 361-364, 2008 ISSN 1721-8861 Harmonia axyridis recordings in northern Italy 1 1 1 1 1 Giovanni BURGIO , Fabrizio SANTI , Alberto LANZONI , Antonio MASETTI , Valentino DE LUIGI , 2 3 4 5 1 Massimiliano MELANDRI , Alberto REGGIANI , Carlo RICCI , Antoon J. M. LOOMANS , Stefano MAINI 1Dipartimento di Scienze e Tecnologie Agroambientali - Entomologia, Università di Bologna, Italy 2Terremerse, Bagnacavallo, Ravenna, Italy 3Centro Agricoltura e Ambiente “G. Nicoli”, Crevalcore, Bologna, Italy 4Dipartimento di Scienze Agrarie e Ambientali, Università di Perugia, Italy 5Department of Entomology, National Reference Laboratory, Plant Protection Service, Wageningen, The Netherlands Abstract In summer 2008, larvae, pupae and adults of Harmonia axyridis (Pallas) (Coleoptera Coccinellidae) were found in several locali- ties in northern Italy. Since the first record in Turin (Piedmont) in 2006, this ladybird, just two years later, was collected up to the northeast of Italy. The colour forms found consisted for 97.52% of H. axyridis succinea and 2.48% of H. axyridis spectabilis (n = 1049). These records may represent a case study in modelling intra-guild predation and the spread of an exotic species. Key words: exotic species, establishment, Italy, Harmonia axyridis, form succinea, form spectabilis, Coleoptera, Coccinellidae. Introduction Materials and methods The multicoloured Asian or harlequin ladybird beetle Visual samplings were carried out, in a scattered way, Harmonia axyridis (Pallas) (Coleoptera Coccinellidae) is since 2000 focusing particularly on the garden of Fac- considered as invasive exotic species in Europe and ulty of Agriculture, Bologna University. After the first North America (Brown et al., 2008). Recently, some re- finding in Emilia-Romagna region on June 29, 2008, views on H. axyridis focused on the ecology, biology, near Verucchio, the sampling effort was increased. H. spread, distribution, biological application and potential axyridis was monitored directly by visual observations impacts of this coccinellid (Koch, 2003; Majerus et al., made by the authors and also asked our colleagues in 2006; Pervez and Omkar, 2006). A synthesis of research Italy. The samplings were conducted in the rural envi- on H. axyridis, providing current perspective and future ronments potentially subject to the colonization by H. directions, was published (Roy and Wajnberg, 2008). Be- axyridis, such as orchards, arable crops, hedgerows, iso- sides questions related to the ecological risks of this ex- lated trees and field margins. H. axyridis was also moni- otic ladybird species, as synthesized in the cited book, tored in some urban environments such as houses, there is also an interest in following its spread and the buildings, gardens and boulevards. dynamics of its potential geographic distribution by keep- The monitoring programme was employed in a quali- ing records uptodate (P. M. J. Brown, in litteris). For its tative way, by recording the presence of larvae, pupae biological features, H. axyridis is considered a case study or adults in case of localities with high populations of in modelling the spread of an exotic species. Simulation the coccinellids, and eventually counting the larval and models were used to predict the establishment potential adult specimens that were collected for the identifica- of this coccinellid (Poutsma et al., 2008). Concern about tion in the laboratory. The colour forms of specimens asymmetric intra-guild predation (IGP) is also an impor- collected were counted in three localities (Crevalcore, tant topic to evaluate in new colonized areas. Up to now, Modena and Nonantola). bioassays in Italy were only performed in the laboratory The sites in which H. axyridis was recorded were (Burgio et al., 2002; 2005) and experiments on predation mapped using Google Earth (©2007 GoogleTM), provid- under semi-field conditions (Burgio et al., 2008). More- ing the coordinates of each site and including also the over, the capability to overwinter was demonstrated for characteristics of the investigated habitats (figure 1). artificially reared individuals (Bazzocchi et al., 2004). From 1995 to 1999 adults of H. axyridis were released in Italian protected crops as beneficial biological control Results and discussion agents of pest aphids (Orlandini and Martellucci, 1997). The commercialization was eventually discontinued due The sites where H. axyridis has been recorded are re- to the suspected invasiveness. ported in table 1 and represented in figure 1. In addition In October 2006, the first feral H. axyridis adults and internet records have occurred in 2008 as well. As only pupae (approximately 30 specimens) were detected in some of these could be confirmed, these are not included an urban area of Turin (Piedmont, northwest Italy). In in the map. Most of the specimens belonged to the suc- 2007 a few adults were observed again in the same re- cinea form (Seo et al., 2008). Between the melanic forms gion (Brown et al., 2008) and first anecdotal record (spectabilis and conspicua) only the spectabilis was from Lombardy occurred on the internet. In the present found in a very low percentage (no conspicua colour pat- note we report the detection of this species in several tern was detected). The data on the last generation (mi- new locations in northern Italy. grant adults) were as follows: 97.68% succinea (n = 992, Table 1. Localities in northern Italy in which H. axyridis was recorded. Data updated till the end of October 2008. Localities were ordered from North to South. Code Locality Region Coordinates Plant/habitat Tarcento Friuli-Venezia 46°12'48.99"N Garden (adults) 1 (Udine) Giulia 13°12'50.10"E sample collected by I. Bernardinelli San Fedele 46°11'42.77"N 2 Lombardy Hibiscus sp. (2 larvae) (Sondrio) 9°27'4.59"E Sueglio 46°5'12.20"N 3 Lombardy Garden (2 pupae, 2 adults) (Lecco) 9°20'5.47"E Martignacco Friuli- 46°5'32.31''N House (1 adult) 4 (Udine) Venezia Giulia 13°7'49.85''E sample collected by P. Zandigiacomo Vestreno 46°5'3.19"N 5 Lombardy Hibiscus sp. (2 adults), garden hedge (20 larvae) (Lecco) 9°19'33.55"E Corenno 46°4'55.26"N 6 Lombardy Buddleja davidii (larvae and adults) (Lecco) 9°18'38.95"E Dervio 46°4'21.85"N Umbelliferae grass strips (2 mating adults), 7 Lombardy (Lecco) 9°18'13.64"E Prunus spinosa (1 adult) Bellano 46°2'25.60"N 8 Lombardy Hibiscus sp. (1 adult) (Lecco) 9°18'12.56"E Menaggio 46°1'12.06"N 9 Lombardy Nerium oleander (1 adult) (Como) 9°14'22.65"E 45°51'10.74"N 10 Lecco Lombardy Tilia platyphyllos (2 adults) 9°23'24.25"E Cascina Barera 45°24'8.66"N Maize (adults) 11 Lombardy (Milano) 9°0'42.60"E samples collected by G. Camerini Legnaro 45°21'11.95''N Garden (adults) 12 Veneto (Padua) 11°57'4.28''E samples collected by V. Girolami Maleo 45°10'12.00"N Maize (adults) 13 Lombardy (Lodi) 9°46'29.99"E samples collected by L. Garioni Codogno 45°9'44.00"N Maize (adults) 14 Lombardy (Lodi) 9°43'15.00"E samples collected by L. Garioni Somaglia 45°8'48.02"N Laurus nobilis (adults preying Ceroplastes sp.) 15 Lombardy (Lodi) 9°38'14.37"E samples collected by L. Garioni Chierichezze 45°6'58.00"N Maize (adults) 16 Lombardy (Lodi) 9°39'39.00"E samples collected by L. Garioni Bastida Pancarana 45°5'10.27"N Maize (adults) 17 Lombardy (Pavia) 9°4'56.54"E samples collected by G. Camerini Bressana Bottarone 45°4'44.03"N Maize (adults) 18 Lombardy (Pavia) 9°7'58.79"E samples collected by G. Camerini Castelletto di Branduzzo 45°4'13.36"N Maize (adults) 19 Lombardy (Pavia) 9°5'56.03"E samples collected by G. Camerini Polesine Parmense 45°1'16.18''N 20 Emilia-Romagna Garden (adults) (Parma) 10°5'33.08''E Occhiobello 44°53'55.83"N Ficus carica (adults) 21 Veneto (Rovigo) 11°36'23.04"E samples collected by R. Ferrari and M. Pozzati 44°49'50.71"N 22 Parma Emilia-Romagna Hedgerows (adults) 10°20'14.60"E Novi Ligure 44°44'19.53''N House (adults) 23 Piedmont (Alessandria) 8°46'49.64''E samples collected by F. Panella Ravarino 44°43'25.42"N 24 Emilia-Romagna Vineyard (adults) (Modena) 11° 5'59.88"E Crevalcore 44°43'17.67"N 25 Emilia-Romagna Maize and houses (adults) (Bologna) 11°9'3.47"E Castello d’Argile 44°41'0.08''N House (adults) 26 Emilia Romagna Bologna 11°18'6.15''E samples collected by A. Puggioli Nonantola 44°40'35.76"N 27 Emilia-Romagna Acer campestre and house (adults) (Modena) 11°2'7.38"E 44°39'14.26"N 28 Modena Emilia-Romagna House (adults) 10°53'31.28"E 44°30'52.14"N 29 Bologna Emilia-Romagna Garden (mixed population of larvae, pupae and adults) 11°24'19.38"E Crespellano 44°30'41.07"N 30 Emilia-Romagna House (4 adults) (Bologna) 11°7'53.67"E Monteveglio 44°28'18.00"N 31 Emilia-Romagna Vineyard (adults) (Bologna) 11°6'6.75"E Castello di Serravalle 44°26'09.89"N 32 Emilia-Romagna Vineyard (1 adult) (Bologna) 11°07'09.74"E (Continued) 362 (Table 1 Continued) Code Locality Region Coordinates Plant/habitat Sasso Marconi 44°24'1.73"N 33 Emilia-Romagna Hedgerow (1 adult) (Bologna) 11°15'2.33"E San Bartolo 44°21'4.58"N 34 Emilia-Romagna Peach orchard (adults) (Ravenna) 12°12'54.99"E Imola 44°21'21.29"N 35 Emilia-Romagna House (1 adult) (Bologna) 11°42'58.03"E Monterenzio 44°19'39.93"N 36 Emilia-Romagna Arbutus unedo (mixed population of larvae and adults) (Bologna) 11°24'21.29"E Pinarella 44°14'31.59"N 37 Emilia-Romagna Pine forest (adults) (Ravenna) 12°22'12.08"E Verucchio 43°58'59.97"N 38 Emilia-Romagna Rosa sp.